"""
Authentication Utilities for TaskMaster v1
AceFlow v3.0 - Implementation Phase

Provides password hashing and JWT token management
"""

import os
from datetime import datetime, timedelta
from typing import Optional
from passlib.context import CryptContext
from jose import JWTError, jwt

# Password hashing configuration
pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")

# JWT configuration - Load from environment variables
SECRET_KEY = os.getenv("SECRET_KEY", "CHANGE_THIS_SECRET_KEY_IN_PRODUCTION")
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = int(os.getenv("ACCESS_TOKEN_EXPIRE_MINUTES", "30"))


def verify_password(plain_password: str, hashed_password: str) -> bool:
    """Verify a password against its hash"""
    return pwd_context.verify(plain_password, hashed_password)


def get_password_hash(password: str) -> str:
    """Hash a password for storing"""
    return pwd_context.hash(password)


def create_access_token(data: dict, expires_delta: Optional[timedelta] = None):
    """Create JWT access token"""
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.utcnow() + expires_delta
    else:
        expire = datetime.utcnow() + timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)

    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


def verify_token(token: str) -> Optional[dict]:
    """Verify and decode JWT token"""
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        return payload
    except JWTError:
        return None


def get_user_id_from_token(token: str) -> Optional[int]:
    """Extract user ID from JWT token"""
    payload = verify_token(token)
    if payload and "sub" in payload:
        try:
            return int(payload["sub"])
        except ValueError:
            return None
    return None
